פירוש על עבודה זרה 100:9

Again, the Talmud tries to claim that our baraita, which allows smearing oil on the tree, contradicts another baraita which allows smearing oil on unripe figs but only before the Sabbatical year, not on the Sabbatical year itself. But again, this is not really a difficulty. In our case the oil is being smeared on the tree to preserve it after it was pruned. Again, preserving the tree is permitted. But smearing oil on unripe figs is to fatten them up and it is prohibited.